12212552778 has 16 divisors (see below), whose sum is σ = 25085244000. Its totient is φ = 3960827856.

The previous prime is 12212552771. The next prime is 12212552789. The reversal of 12212552778 is 87725521221.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (12212552771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27505528 + ... + 27505971.

It is an arithmetic number, because the mean of its divisors is an integer number (1567827750).

Almost surely, 2^12212552778 is an apocalyptic number.

12212552778 is an abundant number, since it is smaller than the sum of its proper divisors (12872691222).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12212552778 is a wasteful number, since it uses less digits than its factorization.

12212552778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55011541.

The product of its digits is 156800, while the sum is 42.

The spelling of 12212552778 in words is "twelve billion, two hundred twelve million, five hundred fifty-two thousand, seven hundred seventy-eight".